C12E9
DTC C0110, C12E0, C12E8, or C12E9
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructionsprovides an overview of each diagnostic category.
DTC Descriptors
DTC C0110 00
- Pump Motor Circuit
DTC C0110 61
- Pump Motor Circuit Actuator Stuck
DTC C12E0 00
- ABS Pump Motor Performance
DTC C12E8 00
- ABS Pump Motor Stuck
DTC C12E9 00
- ABS Pump Motor Stuck On
Diagnostic Fault Information
Circuit/System Description
The pump motor is a bi-directional motor and is an internal part of the brake pressure modulator valve assembly. There are three solid state relays in the electronic brake control module (EBCM) that operate the pump. The pump motor runs every few brake stops in order to fill the high pressure accumulator with brake fluid anytime the engine is running.
Conditions for Running the DTC
* Ignition ON.
* Ignition voltage is greater than 10 volts.
* The system enable relay is ON.
* The pump motor has been commanded ON, OFF and ON again.
Conditions for Setting the DTC
* The EBCM detects a short to ground or an open/high resistance on the B+ circuit.
* The EBCM detects an open/high resistance on the ground circuit.
* The EBCM detects the pump motor runs continuously.
* The EBCM detects the pump motor is binding or stalled.
Action Taken When the DTC Sets
* The EBCM disables the ABS/Traction Control System/Vehicle Stability Enhancement System for the duration of the ignition cycle.
* The ABS indicator illuminates.
* The red Brake indicator illuminates.
* The Stability Control indicator illuminates.
* The driver information center displays Service Brake Soon, Service StabiliTrak and Service Traction Control messages.
Conditions for Clearing the DTC
* The condition for the DTC is no longer present and the United Nations Economic Commission for Europe regulation number 13 response is completed by driving the vehicle at speeds greater than 15 km/h (10 mph) to complete the self test, then the EBCM will turn off the ABS indicator.
* The EBCM clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles.
Diagnostic Aids
* Find out from the customer the conditions under which the DTC was set. This information may help duplicate the failure like the specific number of brake pedal applies in a row prior to the fault set.
* Check for hydraulic leaks, air in the brake system or an improper brake bleed.
Reference Information
Schematic Reference
Antilock Brake System Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
ABS Description and Operation ABS Hybrid
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Programming and Relearningfor scan tool information
Circuit/System Verification
1. Ignition ON, perform the ABS Motor test with a scan tool. You should hear or feel the ABS pump motor turn ON and OFF.
• If the pump motor does not turn ON and OFF, refer to Circuit/System Testing.
Note: To ensure the complete brake modulator and high pressure accumulator pressure relief procedure is allowed to occur, the brake controller must see one brake pedal apply with the engine running followed by a proper shutdown without applying the brake pedal.
2. Transmission in PARK, engine running, apply and release the brake pedal.
Note: The ignition must transition to the OFF position without pausing at ACCESSORY and without applying the brake pedal. This ensures that the brake modulator and high pressure accumulator relief occurs. This process will take approximately 1-2 minutes.
3. Ignition OFF, key removed from the ignition, wait 2 minutes.
4. Ignition ON, observe the scan tool EBCM, Accum. Pressure Sensor parameter. The Accum. Pressure Sensor parameter should be greater than 18,000 kPa (2,600 psi) in less than 30 seconds.
• If less than 18,000 kPa (2,600 psi) or it takes longer than 30 seconds to build pressure, refer to Brake Hydraulic and Assist System Diagnosis Brake Hydraulic and Assist System Diagnosis.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the K17 EBCM.
2. Test for less than 1 ohm between the ground circuits listed below and ground:
* Terminal 13
* Terminal 38
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuits listed below and ground:
* Terminal 25
* Terminal 1
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, replace the Q5 brake pressure modulator valve assembly.
4. If all circuits test normal, replace the Q5 brake pressure modulator valve assembly and verify DTC does not reset. If the DTC resets, replace the K17 EBCM.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Brake Pressure Modulator Valve Replacement Service and Repair
* Control Module References Programming and Relearningfor EBCM replacement, setup, and programming